Job searching is a competition, as I've said many, many times (sorry if you're tired of hearing it). It's not just about your qualifications and how they compare to a job posting, it's about how your qualifications and your conduct compares to everyone else who is applying for the same thing.
The entire job search process can be considered a "test" by the recruiter. It's your first chance to demonstrate your character and skills - and that could play a huge factor in determining whether you get selected for an interview. Past experience and achievements are very important, but so are your actions during the application process.
Here are some things to keep in mind:
Are you following application instructions?
If the job posting says to email your resume to a particular email address, don't simply comment and say, "I'm interested - check out my profile." That tells the recruiter that you're not capable of following instructions. If you can't do what you're told to do in the application process, how can you on the job?
Are you paying attention to detail?
Did you send it to the right email address? Did you spell the person's name correctly? Did you attach the information requested? If you miss important details, or any details for that matter, you're telling the recruiter something about how careful and organized you are. Take a moment to dot your i's and cross your t's.
Are you meeting timelines?
I don't just mean the deadline for sending in your resume. Are you doing everything on schedule? Did you follow-up when you said you would? Did you send your references when you said you would? Getting things done on time is important in our daily work lives, and it's important in the job search process as well.
Are you researching companies beforehand?
Recruiters want to hire top performers, but they also want to hire people who really want to work for their company. They can tell if you've taken the time to learn what you can about the company you say you want to work for. If you haven't, it says something about you.
Are you putting in your best effort by customizing your resume and cover letter?
Don't send the same, stale cover letter to everyone - customize it for each job you apply for. Use the knowledge you gained through your research to demonstrate why you're a great fit. Recruiters can tell if you took that extra step (they'll ignore generic cover letters).
Are you a clear and professional communicator?
Verbal and written communication skills are extremely important today. Don't waste time telling them that you're a great communicator on your resume, demonstrate it in every interaction - in comments on a job posting, through email, on the phone, and in person. Skip the shorthand "texting" stuff and be professional.
The bottom line: If you don't have the qualifications for a particular job, you're not going to be considered, no matter how hard you try. But on the flip side, having the qualifications doesn't make you a shoo-in either. All that does is get you past the first gate. How you conduct yourself will play a part in whether you get through any more.
Hope that helps!